Stock exhaust vs shorties, off-road H, and a catback

[1986Browns]

How much additional power and torque (at the real wheels...NOT at the flywheel) could one expect when removing all of the stock exhaust and replacing it with some nice un-equal length shorty headers, off-road H-pipe, and a Flowmaster catback kit? Also, how big of a "seat of the pants" difference would changing out the exhaust system make?

[Romo93]

I would say no more than 25hp, maybe a little less.

[WillyB93]

Probably not that much, but sure will grab attention faster with that unique sound of flowmaster's on a mustang.

[Z282SLO]

Awhile back, I put on an off-road H pipe and flowmasters on my 89 GT and the shop that did the install estimated a 10% power increase at the rear wheels (leaving the stock headers). Changing out the headers should gain you another 5-10%.

There is a noticeable difference when the stock exhaust and cats are removed. My Cobra has long tubes, off road H pipe and flowmasters and the sound is quite enjoyable.

[1986Browns]

My Cobra has long tubes, off road H pipe and flowmasters and the sound is quite enjoyable.

Got any YouTube vids?!?!?

[vinchez78]

My Cobra has long tubes, off road H pipe and flowmasters and the sound is quite enjoyable.

Got any YouTube vids?!?!?

Same set up here, I may hold off on speakers since I love the sound of the exhaust

[Z282SLO]

My Cobra has long tubes, off road H pipe and flowmasters and the sound is quite enjoyable.

Got any YouTube vids?!?!?

Not yet ... planning on posting one soon.

[1986Browns]

My Cobra has long tubes, off road H pipe and flowmasters and the sound is quite enjoyable.

Got any YouTube vids?!?!?

Not yet ... planning on posting one soon.

I've got my popcorn ready

[Romo93]

My Cobra has long tubes, off road H pipe and flowmasters and the sound is quite enjoyable.

Got any YouTube vids?!?!?

Not yet ... planning on posting one soon.

A nice throaty exhaust with a WHISTLE!

[mkeane93]

FRPP Shorty Headers, MAC pro-chamber, Flowmaster 40 series cat-back 3.73 FRPP gears & aluminum driveshaft, MGW shifter, this is my setup on mine, heres a video of exhaust sound...
http://www.youtube.com/watch?v=KI4-LbMRtbA

[1986Browns]

I know what the physical differences are between the Mac ProChamber and a regular off road H-pipe...but is there any sound difference or real performance advantage to the ProChamber?

BTW, that combo does sound good!

[mkeane93]

I know what the physical differences are between the Mac ProChamber and a regular off road H-pipe...but is there any sound difference or real performance advantage to the ProChamber?

BTW, that combo does sound good!

thanks, previous owner installed it, I like the sound of it

[Just93]

I have shorty headers, off road h pipe and had flow masters on my car, I took off the flow masters and installed a magnaflow cat back system. I was a little unsure but I'm much happier with it! They sound very similar at idle and cruise but when you on the loud pedal hard it has a much more aggressive tone.

[1986Browns]

C'mon guys!!

[BrettT]

Here's a couple vid's


Ford Shorties, mac prochamber, flowmaster cat-back



Mac headers, h-pipe, flowmaster cat-back.